Delivering results for difficult to express proteins
Based on more than 30 years of innovation in microbial biotechnology, we offer a complete range of strain development services using our XS Microbial Expression Technologies®. No single host type or vector is capable of being the best expression option for all types of recombinant proteins. To address this, our portfolio of powerful expression tools includes three E. coli, three P. pastoris and two B. subtilis systems. We recently introduced our Pichia 2.0 system that uses a new proprietary inducible promoter, a shorter screening process and has produced high, multi-gram per liter titers with short fermentation times. Our toolbox of strain design options provides the greatest probability of delivering soluble product while overcoming other expression challenges.
During an initial discussion, we gather information about your expression goals including physico-chemical properties and experimental history of your target protein. Based on this information, our strain development scientists design an XS® strain feasibility program tailored to meet your future milestones. The program design is based on a rational selection of hundreds of host-vector options for all or selected hosts that will offer the greatest chance of meeting a desired outcome. Strain development begins with cloning of the selected expression plasmids. After transformation, hundreds of clones can be generated and primary screen performed in four weeks. This approach maximizes the chance of success while minimizing the timeline. Scientists conduct a secondary screening stage which takes approximately two weeks, where the top candidates are evaluated in small scale fermenters to select your best production strain. The scale of the fed-batch fermentation runs can be selected from 0.25 L to 2 L to provide the required purified milligram quantities of your protein for further in-house testing.